Patent GB-1300302-A (GB)
Title: Turbine-compressor assemblies
IPC: F04D25/04
Filed: 1970-08-24
Abstract: 1300302 Centrifugal compressors; steam turbine plant; turbine stop gear INGERSOLL - RAND CO 24 Aug 1970 [30 Sept 1969] 40655/70 Headings F1C F1K F1Q and FIT A turbine-compressor unit comprises a housing containing a steam turbine 26, Figs.1 and 2 directly coupled to a compressor comprising stages 16, 17, 18 each having an impeller integral with the compressor shaft 20 and rotatable within a shroud formed of the housing: and journal bearings 54 resiliently mounted to the housing by adjustably spring-loaded restrainers and provided with dry lubrication. The turbine has a inlet port 31, and exhausts to an exhaust port 34 via a volute 32 and a chamber 33. The compressor receives gas through a central inlet pipe 10 and discharges the compressed gas via an annular chamber 14 and heat exchanger tubes 15 to an outlet port 13. Coolant enters and leaves the heat exchanger via ports 12. The compressor has labyrinth seals 22-25 and the turbine has a duel labyrinth seal 35 from which leakage is removed via an annular chamber 37, a duct 36 and scavenge conduits 38, 39. The bearings 54 are lubricated by gas. The turbine rotor 26 cooperates with a steam-borne thrust ring 41 and a fixed wear ring 42, steam for thrust-balancing and for a lubricant film between the rotor and the rings being supplied via conduits 45-52 to axial ports 44 in the rings and vented via scavenge conduits 53 drilled radially through each ring. Screws 57 permit adjustment of the clearance between walls 58, 58' and the compressor impeller blades. Six turbine-compressor units may be combined as shown in Fig.3, with a common steam inlet pipe 59 connected via a toroidal manifold 60 and individual pipes 61 to the steam inlets of the units. The individual steam exhaust pipes 63 are connected via a manifold 62 to a common exhaust pipe 64. Gas enters the compressor of the first unit 66 via an inlet pipe 65 and passes in series through the compressors of the successive units, which are inter-connected by pipes 67, the compressed gas being taken from the sixth unit 70 via an outlet pipe 69. The pipes 65, 69 are inter-connected by piping 72, 73 containing a shutoff valve 74, to permit recirculation of the gas when, as during starting, the speed is insufficient to provide the required compression. In each turbine-compressor unit the speed and excursions of the shaft 20, the pressure of gas supplied to the bearings 54 and the compressor seals and exhausted therefrom, and the exhaust steam pressure are monitored, automatic control of steam supply in accordance with shaft speed and automatic control of throttle valves in the gas supply and exhaust lines in accordance with the gas pressures being effected, and if any of the monitored values are excessive, an alarm is actuated and, after an interval determined by a timer, a valve is automatically closed to shut off the supply of steam to that unit. During start-up air is removed from the compressor system, prior to introduction of hydrogen gas to be compressed, by using a vacuum pump or by purging with nitrogen or an inert gas. A similar procedure is used after shut-down.